[A-CG45] AsiaPEX field campaign strategies for changing Asian monsoon precipitation

[ACG45-04] The Unprecedented August 2024 Eastern Bangladesh Flood: A Study of Hydrometeorological Drivers, Societal Impacts, and Policy Needs for Resilience

*Mohan Kumar Das^1,2,3,4, Md. Awlad Hossain^1,5,2, Sheikh Fahim Faysal Sowrav^1,2,4, Toru Terao⁶, Nafis Imtiaj Hossain¹, Md Sazzad Hossain^1,7, Maisha Farzana Methila^1,3,2, Puspendu Biswas Paul ^1,10, Jamal Uddin Khan^1,8, Mahfujur Rahman^1,2,11, Samarendra Karmakar^12,1,2, A.K.M. Saiful Islam^1,11, Md. Shameem Hassan Bhuyian^12,1, Faruque Abdullah^1,2, Sifat Tanzil Ovi ^1,2,3, Swapan Chandra Barman^1,2, Arpita Roy Shawon^1,2,13, Ayan Debnath ^14,1,2, Ishrar Tahmin Anika ^1,15, Shipa Rani Singha ^1,2,3, Rakesh T. Konduru⁹, Md. Khurshed Alam¹, Fatima Akter^1,2,3, Monika Dhar¹, Khan Mohammad Ibtehal^1,2,4, Md. Sajid Anam^2,1,4, Al Amin Arrafi ^1,2,4, Shakil Hossen^1,2,16, Atika Afia Broty^1,2,4, Shekhar Kanti Ray¹ (1.National Oceanographic And Maritime Institute (NOAMI), 70 Bir Uttam C R Dutta Road, Hatirpool, Dhaka-1205, Bangladesh, 2.South Asian Meteorological Association (SAMA), Mausam Bhawan, Lodhi Road New Delhi - 110003, India, 3.Department of Meteorology, University of Dhaka, Dhaka-1000, Bangladesh, 4.Department of Oceanography and Hydrography, Bangladesh Maritime University, Dhaka, Bangladesh, 5.Department of Applied Mathematics, University of Dhaka, Dhaka-1000, Bangladesh, 6.Faculty of Education, Kagawa University 1-1, Saiwai-cho, Takamatsu, Kagawa 760-8522, Japan, 7.Bangladesh Water Development Board , 72 Green Road, Dhaka-1205, Bangladesh , 8.Laboratoire d’Etudes en Géophysique et Océanographie Spatiales (LEGOS), Université Toulouse III, CNRS, CNES, IRD, Toulouse, France, 9.Centre for Computational Science, RIKEN Cluster for Pioneering Research, Prediction Science Laboratory, RIKEN, Kobe, Hyogo, Japan, 10.International School, Regional Centre for Space Science and Technology Education in Asia and the Pacific (RCSSTEAP), Beihang University, 37 Xueyuan Road, Haidian District, Beijing, P.R. China, 100191, 11.Institute of Water and Flood Management (IWFM), Bangladesh University of Engineering and Technology (BUET), Dhaka 1000, Bangladesh, 12.Bangladesh Meteorological Department, Meteorological Complex, Agargaon, Dhaka-1207, Bangladesh, 13.Department of Geography and Environment, University of Dhaka, Dhaka-1000, Bangladesh, 14.Geography and Environmental Studies, University of Chittagong, Chattogram, Bangladesh, 15.Institute of Disaster Management and Vulnerability Studies, University of Dhaka, Dhaka-1000, Bangladesh, 16.Department of Oceanography, Noakhali Science and Technology University, Noakhali, Bangladesh )

Keywords:Monsoonal Low Pressure, Transboundary Flooding, Catchment Hydrodynamics, Impact-Based Forecasting, Early Warning Systems

The August 2024 flood in Eastern Bangladesh was one of the most severe in recent history, causing significant human and economic losses. This study provides a comprehensive analysis of the hydrometeorological drivers, societal impacts, and policy implications necessary for building resilience. Using remote sensing, GIS, and numerical modeling, the research investigates extreme precipitation, river hydrodynamics, and forecasting limitations. INSAT imagery and BAF Doppler Weather Radar detected intense monsoonal convection, while WRF simulations indicated cyclonic circulation at 850 hPa. Feni Station recorded 346 mm of rainfall within 24 hours, with similar observations from GPM data, leading to severe flooding in the Feni and Muhuri River basins. Subsequently, extreme rainfall and water flow caused additional inundation in the Gomti River and Lakshmipur Canal regions. Field surveys quantified human displacement, infrastructure damage, and economic losses, while hydrological assessments examined transboundary flood risks arising from catchment interactions with Tripura, India. To better understand such events, field experiments are essential. The AsiaPEX (Asian Precipitation Experiment), launched as a successor to GEWEX's GAME and MAHASRI projects, aims to improve understanding of terrestrial precipitation across diverse hydroclimatological conditions. It focuses on key research areas such as precipitation observation, land-atmosphere coupling, subseasonal to interdecadal predictability, high-resolution hydrological modeling, coordinated field campaigns, and climate change detection, with particular emphasis on the Asian monsoon system. The findings reveal critical deficiencies in impact-based forecasting and highlight the urgent need for integrated early warning systems that assimilate real-time meteorological and hydrological data, as demonstrated in field experiments such as AsiaPEX. Strengthening transboundary flood management and community-based resilience programs will be essential for reducing future risks and improving regional preparedness.